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    <meta charset="UTF-8">
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    <title>Document</title>
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<body>
    <script type="text/javascript">
        function Foob(b) {
            this.a = b;//a->b
        }
        var obj1 = {}
        var bar = Foob.bind(obj1)
        bar(2)

        console.log(obj1.a);//2
        var baz = new bar(3);
        console.log(obj1.a);//2
        console.log(baz.a);//3

    </script>
</body>
</html>